Stone Disease: New AUA guide discusses SWL vs. URS

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Other key stone disease/endourology topics from the 2016 AUA annual meeting included the use of aspirin in percutaneous nephrolithotomy patients as well as the continuing debate over the benefit of medical expulsive therapy.

Jodi Antonelli, MDOther key stone disease/endourology topics from the 2016 AUA annual meeting included the use of aspirin in percutaneous nephrolithotomy patients as well as the continuing debate over the benefit of medical expulsive therapy. The stone disease/endourology take-home messages were presented by Jodi Antonelli, MD, of the University of Texas Southwestern Medical Center, Dallas.

The new AUA/Endourological Society guideline on the surgical management of stones provides insight into imaging, preoperative testing, and the treatment of renal and ureteral stones in adults, children, and pregnant women. The guideline includes indications for active surveillance and surgical treatment, recommendations for surgical approach, and broadened indications for ureteroscopy over shock wave lithotripsy.

The learning curve for ultrasound-guided percutaneous nephrolithotomy may be as short as 20 cases, and adoption of this technique may dramatically reduce radiation exposure for patients and providers. Physicians improved over consecutive cases, with fluoroscopic screening time decreasing from 79.2 seconds over the first 20 cases to 11.1 seconds in the last 20 and success in puncture increasing from 30% over the first 20 cases to 100% in the last 20 cases.

The novel laser direct alignment radiation reduction technique for PCNL access showed impressively low access and total fluoroscopy times in an initial 25 cases. This may be a safe way to perform PCNL with reduced radiation exposure.

In patients with stones 5-20 mm in size, active basket extraction had a higher stone-free rate at 3 months compared to dusting but didn’t demonstrate a difference in other areas such as symptoms, reintervention, and readmission rates. Extended follow-up may provide more information.

PCNL may be safely performed in patients on aspirin. No significant differences in residual fragments, perioperative change in hemoglobin, hematocrit, and creatinine, or 30-day complication rate (bleeding or thrombotic events) were found in patients on aspirin therapy compared to those who were not.

Continue to the next page for more take-home messages.

The overall risk of bleeding was 3.3% in PCNL patients on anti-platelets and anticoagulants, with 18 of 540 PCNL cases experiencing significant bleeding, of whom 10 required embolization.

PCNL is safe in the super-obese population. Additionally, two separate studies found PCNL can be safely performed in the ambulatory setting.

Multiple abstracts evaluated the role of medical expulsive therapy in treating stones. One found that silodosin (Rapaflo) increased rate of stone expulsion and decreased time to passage in adults with distal stones 5-10 mm in size. A separate study found that in pediatric patients, silodosin had no benefit for rate of stone expulsion but decreased time to passage and pain.

A systematic review of alpha-blockers including more than 5,600 patients found no benefit for the use of medical expulsive therapy in small ureteral stones but showed a 58% higher rate of stone passage with larger stones, as well as a reduced likelihood of urologic intervention for patients with lower ureteral stones.

A systematic review of trials of alpha-blockers and nifedipine found that overall, these medications were statistically significantly more likely to lead to stone expulsion. However, a subgroup analysis of powered RCTs with low risk of bias found no benefit. Combining the overall studies and subgroup analysis, alpha-blockers showed a shorter time to passage and improved passage of larger distal stones.